As one of the most disappointing seasons in franchise history winds to a close, the Blue Jays are taking stock of their future. Which players could be key contributors in 2018? And which ones could be key building blocks for years to come?

A few months ago, many people would have included Roberto Osuna as one of those foundational players. In Osuna, the Jays have a homegrown prospect who blossomed into a star closer. Just 22 years old, he’d set or approached various records as the youngest player to reach various saves totals. He’d finished fourth in rookie of the year voting in 2015, and was on his way to his first all-star appearance in 2017. With a fastball that could touch the high-90s, a wipeout slider, and the ability to get sellout crowds electrified as soon as his walkup music starts to blare, what was not to like?

As we would soon learn, quite a lot, unfortunately. In the first half of this season, Osuna was a machine, striking out 47 batters, walking...